Method of making steel shells



29, 1961 G. A. LYON 2,997,774

METHOD OF MAKING STEEL SHELLS Filed Jan. 24, 1957 4 Sheets-Sheet 1 Aug.9, 9 G. A. LYON 2,997,774

METHOD OF MAKING STEEL SHELLS Filed Jan. 24, 1957 4 Sheets-Sheet 2 E17 7Eg. 8

ZEYVEH far 650265 /416E7 Zro/v Aug. 29, 1961 e. A. LYON METHOD OF MAKINGSTEEL SHELLS 4 Sheets-Sheet 3 Filed Jan. 24, 1957 FJg.//

7 2 I 3 P w N Z N E N 9 n m 2 E 4 v. a W I n 6A x I AM m 0 Aug. 29, 1961cs. A. LYON METHOD OF MAKING STEEL SHELLS Filed Jan. 24, 1957 4 "SheetsSheet 4 INF-EH fUF 050,06: A5627 [ram United States Patent Z,997,7 74METHOD OF MAKING STEEL SHELLS George Albert Lyon, 13881 W. ChicagoBlvd., Detroit 28, Mich. Filed Jan. 24, 1957, Ser. No. 636,007 4 Claims.(Cl. 29-1.21)

The present invention relates to the making of large size shells andmore particularly steel shells.

An important object of the present invention is to improve the making oflarge size steel shells starting with ingot pieces and ending with thecompleted shells.

Another object of the invention is to provide improvements in the makingof large bomb head shells.

A further object of the invention is to reduce the cost and increase thequality and accuracy of bomb shells of the low drag type.

It is a further object of the invention to provide an improved method ofmaking steel shells directly from ingot pieces and without requiringrolling, and whereby the grain structure of the material is maintainedin the most efiicient orientation throughout the working of the materialfrom the ingot piece to the completed drawn shell.

It is yet another object of the invention to provide improvements in thetreating of the material or blank in the various steps from raw materialto the final drawing or Working operation.

It is also an object of the invention to provide an improved method ofmaking steel shells with a minimum of heating and handling steps.

Other objects, features and advantages of the present invention will bereadily apparent from the following detailed description of a preferredembodiment of the invention taken in conjunction with the accompanyingdrawings, in which:

FIGURE 1 is a fragmental side elevational view of a steel ingot showinghow pieces thereof are prepared for further working according to thepresent method;

FIGURE 2 is a sectional elevational view of a more or less schematicshowing of a dial type press setup for pancaking the ingot pieces;

FIGURE 3 is an enlarged fragmentary sectional detail view takensubstantially along the line IIIIII of FIG- URE 2;

FIGURE 4 is an edge elevational view partially in section of the metalblank after it has been center punched;

FIGURE 5 is a vertical sectional view through the metal blank after ithas been cupped;

FIGURE 6 shows the metal blank after the first draw;

FIGURE 7 shows the blank after a further draw;

FIGURE 8 shows the blank following an additional draw;

FIGURE 9 shows the shell blank after a heading operation;

FIGURE 10 shows the shell after the final elongation drawing operation;

FIGURE 11 shows the shell after a base end portion has been removed;

FIGURE 12 shows the shell after drop ring sockets have been assembledtherewith;

FIGURE 13 shows the shell after back tapering and first nosing; and

FIGURE 14 shows the shell after the final nosing.

In the making of large steel shells such as may be used for the headshell portions of low drag bombs of 500 to 1,000 lb. size, speed ofmanufacture, low cost, uniformity of quality and accuracy in dimensionare important factors.

Cost of material is an important consideration. Ac-

' cording to the present invention instead of using rolled 2,997,774Patented Aug. 29, 1961 slab or stock, pieces of steel ingot ofappropriate size are used. To this end, a steel ingot 15 as it comesfrom the ingot mold is turned down to remove scale and other usualsurface impurities and imperfections. Then, the ingot 15 is cut intopieces of proper length to afford the desired weight of material. Onesuch piece 17 is shown at the large end of the ingot separated from theremainder of the ingot by a saw slot or kerf 18. Where the ingot is ofthe tapering type as shown, the pieces 17 will, of course, be ofgraduated length to compensate for smaller diameters, so that all of thepieces will have the same weight or mass, as separated from the ingot.

In a preferred form, steel of SAE 1330 grade is used. The ingot piecesare heated in a salt bath to a temperature of 2300" F. to 2400 F. Thesalt bath heating has the advantage that it protects the ingot pieceagainst corrosion or scaling and also it requires a minimum of heatingtime and heats uniformly throughout the piece. Such uniform heating ishighly advantageous in that when the uniformly heated piece is pressedto flatten the same, less pressure can be used than where the heating isless uniform.

Each successive heated ingot piece 17 is subjected to longitudinalflattening pressure, that is to pressure applied to the axis of thepiece in order to flatten the same laterally. This may be accomplishedin a press structure as shown in FIGURES 2 and 3. In order to gain asmuch speed with minimum cooling, a dial bed press may be used wherein adial bed 19 is provided with a plurality of stations 20, 20a and 20bwhich may be separated by dividing lines or markers or members 21 andadapted to be successively brought into position under a flatteningpunch 22 (FIG. 3) by turning of the dial bed or turntable 19 (seedirectional arrow in FIG. 2) about an axis 23, which may be provided bya shaft or spindle.

In the first or loading station 20, one of the severed, heated ingotpieces 17 is generally centered in upright position on the bed 19 withina confining, thickness gauging ring member 24 which may be placedloosely and thereby freely laterally adjustably upon the face of the bed19 and is provided with a central sizing opening defined by a sizinginternal periphery 25' that is preferably at least slightly tapered tofacilitate blank removal and in the present instance is shown ascircular in outline. The diameter of the sizing opening and thethickness of the confining plate 24 are predetermined to afford a diskblank or pancake of the required dimensions related to the mass ofmaterial in the ingot piece 17 so that in the pressing of the ingotpiece in the station 20a by ap-' plication of axial flattening pressureby the punch 22 a flattened metal blank B is attained which is of thedesired thickness as gauged by the confining and gauging ring 24 and isof the proper diameter as determined by the confining wall or perimeter25. Since the confining ring 24 is self-adjustable or floating on thebed 19, it can readily adjust itself to any initial eccentricity of theingot piece 17 to the confining perimeter 2.5 as the ingot piece issqueezed and flattened by the flattening punch 22, the perimeter of theblank B then assuming the shape deterrnined by the confining perimeter25 in the final portion of the flattening stroke and until the punch 22.comes to a gauged stop against the confining ring member 24, in thisinstance a substantially perfectly circular perimeter.

Immediately after completion of the pressing stroke, the flatteningpunch 22 is backed off and the dial press bed 19 indexed so that the nowflattened blank B can be removed at the unloading station 20b. This maybe accomplished by engaging the confining and gauging ring 24 in or bysuitable apparatus for transporting the blank to the next workingstation which is preferably equipped to punch a central hole 27 in theblank (FIG. 4) to serve not only as a carrying hold aperture but also asan indexing hole or socket for subsequent drawing operations. Ifpreferred, of course, the dial press bed may be equipped with a punchingstation for providing the central hole 27.

It is preferred to cup and draw the blank B into shell form immediatelyafter flattening and while the same is still possessed of as muchresidual heat as practicable. While the central portion of the blank Bgains some heat due to the severe displacement of material, theperipheral area of the blank by making contact with the confining ring24 loses some of its heat. It is therefore preferable to normalize theblank B after stripping from the confining ring 24, in a salt bathfurnace to a temperature of from 1500 F. to 1800 F. Thereby the centralportion of the blank and the peripheral portion of the blank andthroughout the thickness of the blank attains the same temperature. Thethus temperatureequalized blank is ready for cupping and drawing whichmay, if preferred, be accomplished in automatic dial feed and fastacting presses so as to accomplish a plurality of successive operationsbefore the blank has cooled to the point where it requires reheating orannealing.

As the first drawing operation upon the heat stabilized blank B, it iscupped to provide, as shown in FIGURE 5, a bottom wall 28 and acylindrical side wall 29, with both of the walls about the samethickness and with the material contracted into the cylindrical wall 29present in the elongation of such wall. Immediately thereafter and whilethe cupped blank is still at drawing heat, the side wall is subjected toa first full drawing in which its diameter is reduced and the thicknessreduced while the length of the cylindrical wall is substantiallyincreased, as shown in FIGURE 6.

Before the next or second full draw of the cylindrical wall 29, thetemperature of the partially drawn shell is heat stabilized topreferably 1500 to 1800 F. The second full draw is then completed tosubstantially the shape shown in FIGURE 7. Then the shell blank isannealed at a temperature of about 1260 F., quenched, pickled, andphoscoated. This prepares the shell for further drawing thereof by coldworking the same.

In the third draw which is effected cold, the cylindrical shell wall 29is substantially elongated but the open or mouth or nose end is leftundrawn and thus thicker and of larger outside diameter than theremaining major extent of the cylindrical wall. The result of this thirddraw is depicted in FIGURE 8, showing a thickened external mouth endcollar 30.

In the next step in the proces, the base wall 23 which throughout theseveral elongation draws of the cylindrical wall has remained of thesame thickness, is headed as shown in FIGURE 9 to substantially enlargethe central opening 27 and provide an annular substantially thickenedportion 31 about the enlarged aperture 27. The partially drawn shell isthen annealed, pickled and phoscoated and the cylindrical wall 29subjected to the final elongation draw to the form as substantiallyshown in FIGURE 10. This final elongation draw is facilitated by theshaping during the heading operation of the outside diameter of the basewall 28 to a tapering smaller diameter which at its minimum is about thesame as the final outside diameter of the cylindrical wall 29 atcompletion of the last elongation drawing thereof.

It may be observed that as a result of the several hot and succeedingcold working steps, substantially increased speed is attained andnevertheless a smoothly surfaced product is produced. By effecting thecupping, and first two draws hot and in rapid succession, time delay inheating is reduced to a bare minimum because reheating is minimized ifnot eliminated and any stabilizing to cool down or raise temperature inthe partially drawn shell can be effected quickly. While the hot workingmay leave the surface in a rougher condition than ultimately desired,the cold working operations result in a highly desirable smooth surface.While two cold work drawing operations have been described, additionalone or more cold elongation drawing operations may be added where thesize of the shell requires.

Following the final cold draw, the annular central base portion 31 iscut out, and before or after such cutting out of the base portion, thecollar 30 is subjected to a restrike forming operation wherein anannular tapered mouth surface 32 is provided. The shell now appears asshown in FIGURE 11.

While the opposite ends of the shell are still open to their maximumextent, the cylindrical wall 29 of the shell may be provided with suchopenings therethrough and structural additions thereto as may berequired, for bomb head purposes comprising drop ring or hanger bosssockets 33 as shown in FIGURE 12. Machining for and assembly of the bossor socket members or inserts 33 is substantially facilitated by therelatively free access enabled through the opposite open ends of thetubular shell member.

Thereafter, the shell is subjected to a cleaning operation, the mouthend portion 30 thereof is annealed at 1250 to 1260 F. and then pickled,and phoscoated. The mouth portion 30 is now redrawn to bring the sameinto an outside diameter cylindrically in line with the cylindrical wall29 and to contract the thickened mouth collar to the inside of theshell, as shown in dash outline in FIG- URE 12.

At its nose end portion, the shell is then cold worked to partially nosethe same toward a desired nose ogive as shown in FIGURE 13. Also, thebase end of the shell is back tapered by cold Working the same to thedesired form. This substantially contracts the base end portion 28.

For the final nosing of the shell, substantially the ogive nose endportion of the shell is heated to about 1600 to l800 F. in a salt bathand the final nosing accomplished hot. This results in the finishedshell form shown in FIGURE 14.

Finally, the finished shell is hardened by subjecting the same toheating to about 1600 F. and quenching the same in oil of about F. Thehardened shell may then be tempered or drawn back by heating to 1100 to1150 F. Any finish machining in the nose and base portions of the shellcan then be effected, the shell painted and packed or sent to theassembly lines.

From the foregoing it will be appreciated that the present inventionprovides a shell of uniform grain struc ture since the untrimmed, sizedblank from which it is drawn is derived from an ingot piece that hasbeen fiattened axially to produce a radial grain structure which carriesover into the tubular shell wall as a straight uniform grain from thebase to the tip of the shell and throughout the cross-section thereof.The economy of material thus attained is also important since there areno scrap losses that have usually been attendant upon trimming of ablank to the proper size. Economy is also attained in the high speedcupping and drawing of the blank into the shell form with minimumtreatment intervals for heating or annealing.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim as my invention:

1. In a method of making a bomb head shell, drawing a steel blank intoelongated shell form with a base wall and a tubular wall, shaping thetubular wall at the month end portion thereof into an externallythickened collar, cutting out a portion of the base wall so that accessinto the shell can be had from both ends thereof, securing hanger socketbosses to said tubular wall intermediate the ends thereof, andthereafter back tapering and nosing the shell to substantially reducethe openings at the nose end and at the base end of the shell.

2. A method as defined in claim 1 wherein the nosing is effected in twosteps including 'a first nosing effected substantially coincident withback tapering, then heating the nose end portion of the shell in a saltbath, and final nosing the shell to provide thereon a predeterminedogive.

3. A method according to claim 2, including the further step ofhardening the finally nosed shell, then tempering and final machiningand finishing the shell.

4. In a method of making shells, drawing a metal blank into elongatedtubular wall form with a substantially thicker base wall, heading thebase wall and tapering the periphery of the base wall inwardly fromjuncture with the tubular wall, and then drawing the larger diameterportion of the taper and the tubular wall to an outside diametersubstantially the same as the smaller diameter of the base wallperiphery taper.

6 References Cited in the file of this patent UNITED STATES PATENTS224,765 Bennett Feb. 24, 1880 848,927 Schoen Apr. 2, 1907 1,242,127 BellOct. 9, 1917 2,028,996 Sautier Jan. 28, 1936 2,245,642 Bell Aug. 26,1938 2,286,064 CoXe June 9, 1942 2,350,491 Butler June 6, 1944 2,357,110Heineman Aug. 29, 1944 2,371,716 Snell Mar. 20, 1945 2,404,304 LaytonJuly 16, 1946 2,515,841 Stuart July 18, 1950 2,755,543 Dunn July 24,1956 2,805,466 Lyon Sept. 10, 1957 ,840,884 Biginelli July 1, 1958 OTHERREFERENCES Metals Handbook, 1948 edition published by American Soc. ofMetals, Cleveland, Ohio.

